No Option To Change Existing Human Sim Into Ghost Or Occult

Hi, I am currently playing a teen Sim on PC, through Steam, with The Life And Death expansion pack. In Change A Sim, there is no option to change my Sim into a ghost and the option to change him into an occult is greyed out. I thought players were able to make these changes at any time. Is it because my Sim is currently a Teen? Or, is it another issue? Any help would be greatly appreciated.